PREVOST X3-45 Multiplex, Maintenance Manual

Page: 1165 / 1422

Section 22: HEATING AND AIR CONDITIONING
PA1562
23
2. Open the last L.H. side baggage
compartment door. Pull the black release
button located on the L.H. side in order to
unlock and open the evaporator
compartment door.
3. Remove the evaporator motor and coil
access panel.
4. Identify the L.H. side discharge duct inside
compartment and remove the Phillips head
screws retaining the flexible member to
duct.
5. Repeat step 4 for the R.H. side air duct.
6. Disconnect the electrical motor speed
control connections on the motor plate.
7. From under the vehicle, remove the eight
bolts retaining the evaporator fan motor
support. Remove the complete unit from the
evaporator compartment (Fig. 26 & 27).
FIGURE 26: EVAPORATOR MOTOR ASSY FIXING BOLTS
22315
CAUTION
Never support evaporator motor by its output
shafts while moving it.
8. On a work bench, unscrew the fan square
head set screws, the Phillips head screws
retaining cages to support and slide out the
assemblies from the evaporator motor
output shaft.
7.3.2 Installation
To reinstall the evaporator motor, reverse
"Evaporator Motor Removal" procedure.
FIGURE 27: EVAPORATOR MOTOR ASSEMBLY
7.4 CONDENSER
The central A/C system condenser coil is hinge
mounted on the R.H. side of the vehicle on the
A/C condenser door (Fig. 29). The condenser
coil for vehicles equipped with an auxiliary A/C
system is mounted on the outer face of engine
radiator. Since condenser’s purpose is to
dissipate heat from the hot refrigerant, it is
important to keep the cooling coils and fins
clean. A clogged coil will cause high discharge
pressure and insufficient cooling.
7.4.1 Condenser Fan Motors
Four brushless fan motors (Fig. 28), 28.5 V -
(0.6 HP - 0.42 kW) are installed in the
condenser compartment on R.H. side of vehicle
in order to ventilate the condenser coil. They are
mounted on a support, fastened to the door. The
fans pull outside air through the condenser coil
and discharge it through an opening at bottom of
compartment. When temperature drops inside
condenser, the pressure in the refrigerant line also
drops and it is, therefore, no longer required to
cool condenser. Consequently, when pressure
drops to 130 psi, the motors will run at low speed
and if the pressure continues to drop to 90 psi, a
pressure switch stops the motors so that fans do
not operate needlessly. When pressure rises to
120 psi, the pressure switch reactivates the
motors. If the pressure rises to 170 psi, the motors
will switch to high speed.